(so surprisingly impressive as to stun or overwhelm; "such an enormous response was astonishing"; "an astounding achievement"; "the amount of money required was staggering"; "suffered a staggering defeat"; "the figure inside the boucle dress was stupefying")

2. stupefying

(making physically stupid or dull or insensible; "a stupefying blow to the head"; "the stupefying effects of hemp")

3. stupefying

(shocking with surprise and consternation; "the stupefying impact of the tragedy")